You've measured the room. You know the square footage. But before you place the order, one more number decides whether your project finishes smoothly or stalls out waiting on a second shipment: how much extra to buy.
Order too little, and you're stuck trying to match a new box to an old one that may not be quite the same shade. Order way too much, and you've spent money on flooring that ends up stacked in a garage.
The right amount isn't one universal number. It changes with the material, the layout pattern, and the shape of the room itself. Here's how to think it through before you check out, as one piece of the bigger pre-purchase checklist worth reviewing before any flooring order.
How Much Extra Should You Actually Order?
Most flooring professionals plan for somewhere between about 5% and 20% more material than the room's exact measured area, with the specific product and the layout deciding where in that range a given job lands.
Simple materials in simple, rectangular rooms sit toward the low end. Intricate patterns, natural materials, and oddly shaped rooms push it higher. Treat any number here as a starting ballpark, then confirm it against the flooring's own manufacturer coverage information and with your retailer or installer before finalizing an order.
Why You Need Extra in the First Place
Extra material covers three real things: cuts around the room's edges, colour and pattern matching, and a cushion for mistakes or future repairs.
- Every doorway, closet, and jog around a cabinet or fireplace eats a piece of plank, tile, or carpet that can't always be reused somewhere else in the room.
- Diagonal, herringbone, or chevron layouts waste more material at the room's edges by design, since angled cuts don't line up neatly with square walls the way a straight layout does.
- Natural materials like solid hardwood or stone always include some pieces with grain, colour, or texture an installer won't want to use, and those get set aside before the job even starts.
- A little extra set aside now is what turns a future repair, from a dropped pan, a moved piece of furniture, or a pet's claws, into an easy fix instead of a new colour-matching project.
Getting the room measurements wrong in the first place makes all of this worse. Our common flooring installation mistakes guide covers the measuring and layout errors that tend to cause the biggest overage surprises.
A Ballpark by Material and Layout
The table below is a general starting point pulled from common flooring-industry ranges, not a fixed rule. Product lines vary, so use it to get in the right neighbourhood, then confirm the exact number for your specific product before ordering.
| Material | Straight, simple layout | Diagonal, herringbone, or chevron |
|---|---|---|
| Laminate | Roughly 5 to 8% extra | Roughly 12 to 14% extra |
| Luxury vinyl plank or tile | Roughly 7 to 10% extra | Roughly 10 to 12% extra |
| Engineered hardwood | Roughly 7 to 10% extra | Roughly 12 to 15% extra |
| Solid hardwood | Roughly 10% extra | Roughly 15 to 17% extra |
| Large-format tile (12 inches or bigger) | Roughly 10% extra | Roughly 15% extra |
| Small-format or mosaic tile | Roughly 12 to 17% extra either way, due to more edge cuts and pattern variation between sheets | Same higher range applies |
| Natural stone tile | Roughly 15 to 20% extra, since more pieces get culled for veining or cracks | Toward the higher end of that same range |
| Broadloom carpet | Roughly 10% extra, though roll width matters just as much (see below) | Not a typical layout for broadloom |
| Carpet tile | Roughly 5% extra | Not a typical layout for carpet tile |
Room Shape Changes the Math Too
A simple, square or rectangular room needs less cushion than one with a lot of turns.
Closets, bump-outs, bay windows, stairs, or an L-shaped floor plan stitched together from two rectangles all push toward the higher end of whichever ballpark applies, sometimes a few points above it, since every corner and jog creates its own small offcut. A practical approach many installers use is to break an irregular room into simpler rectangles, measure each one, then add them together, rather than eyeballing the whole shape at once.
Carpet has one more wrinkle worth knowing: it's sold in wide rolls, commonly around 12 feet across, so how a room's actual dimensions divide against that roll width affects how much ends up as scrap, separately from the general percentage above. A flooring specialist can lay this out for a specific room before you order.
A Worked Example
Say a bedroom measures 12 by 14 feet, or 168 square feet, laid out in a straight pattern with engineered hardwood. Using a common straight-layout ballpark of around 8%, that works out to roughly 13 to 14 extra square feet, for a total order in the neighbourhood of 180 to 182 square feet.
Engineered hardwood commonly ships in boxes covering somewhere in the high teens to low twenties of square feet each. That order will likely round up to the next full box anyway, which often means the real-world cushion lands closer to 10 to 12% once the boxes are counted, without doing anything extra.
That rounding-up effect is worth knowing before second-guessing an exact percentage. For the rest of the project planning beyond the order itself, our flooring installation checklist walks through what to have ready before installation day.
Why Box Sizes Make This Easier Than It Sounds
Flooring almost never sells by the exact square foot. It ships in boxes, and each box covers a set number of square feet, printed right on the carton.
Because of that, most orders round up to the next full box regardless of the precise waste percentage calculated on paper, and that rounding often already builds in some of the cushion discussed above. Seeing an order round up isn't a sign too much was purchased, it's just how flooring is packaged. The exact carton coverage varies by brand and plank width, so confirm it for the specific product before checkout. Once your order ships, our flooring delivery guide covers what to expect and how to inspect it when it arrives.
What to Do With the Leftover Material
Keep at least one full, unopened box or bundle once the installation is done, rather than returning every last spare piece.
The reason isn't waste, it's insurance. Flooring is produced in batches, sometimes called production runs or dye lots, and colour can vary slightly from one run to the next, even for the exact same product. If a future repair needs a replacement plank, tile, or carpet patch, material from the original order will match seamlessly. A brand new order placed months or years later might not, and the original run could even be discontinued by then.
Store the extra flat, dry, and out of direct sunlight, and keep a note of the product name and any lot or run information somewhere it won't get lost. That turns a future repair into a quick fix instead of a new research project.
Common Questions About Ordering Extra Flooring
A few of the questions we hear most often once a customer starts working out their order quantity.
What happens if I run out mid-project?
A shortfall usually means waiting on a reorder, and there's a real chance the new material won't perfectly match the original run's colour or finish. This is exactly why ordering a reasonable cushion up front, rather than exactly to the measured square footage, is worth the small extra cost.
Can I return the boxes I don't end up using?
Many retailers, Word of Mouth Floors included, accept unopened, unused boxes within a return window, though restocking or freight charges likely apply and vary by brand. Confirm the specific return terms for a product before ordering, since exact policies differ from one supplier to the next.
Does a professional installer need a different amount than a DIY project?
The material and the room's shape matter more than who is doing the installation. That said, an experienced installer often works more efficiently around cuts and leftover pieces, while a first-time DIY project can benefit from sitting toward the higher end of the ballpark for whichever material is being used.
Is the extra material only there for mistakes?
No. Even a flawless installation still uses extra to get around doorways, closets, and any angled cuts, and the leftover box saved afterward is there for repairs years down the road, not for mistakes made today.
Does carpet need to be calculated differently from hardwood or tile?
Yes, in one specific way. Carpet ships in wide rolls, so how a room's dimensions divide against that roll width matters as much as the general percentage ballpark. A flooring specialist can map this out for a specific room's dimensions before an order is placed.
Getting this number right on paper is one thing. Matching it to the exact coverage of a specific product is another. At Word of Mouth Floors, a modern e-commerce-first flooring retailer, this is one of the most common questions we help customers work through before an order ships.
Order a free sample to check colour and finish in your own space, or contact us and our team can help confirm the right quantity for your project before it ships.
— The Word of Mouth Floors team
hello@wordofmouthfloors.com · (888) 966-3579